Water Quality Study - Southwest Minnesota Public Water Supplies

摘要

Municipal water supplies in the Rock River watershed in Southeastern Minnesota were tested on a monthly basis for two years for the anions nitrate-nitrogen, sulfate, chloride, and bicarbonate alkalinity as CaCO3; and for total dissolved solids, conductivity, and pH. Ratios of the various anions were used to identify changes in water quality not associated with dilution. Seasonal changes in water quality were not necessarily reflected in changes of ratios; concentrations of nitrate-nitrogen increased in many cases, exceeding permissible concentrations specified in the Interim Primary Drinking Water Standards. Groundwater concentrations were compared with surface water samples from the several streams, springs, and lakes in the area, and some correlations were made between land use and groundwater quality and precipitation.